PostgreSQL Source Code  git master
sinval.c File Reference
#include "postgres.h"
#include "access/xact.h"
#include "miscadmin.h"
#include "storage/latch.h"
#include "storage/sinvaladt.h"
#include "utils/inval.h"
Include dependency graph for sinval.c:

Go to the source code of this file.

Macros

#define MAXINVALMSGS   32
 

Functions

void SendSharedInvalidMessages (const SharedInvalidationMessage *msgs, int n)
 
void ReceiveSharedInvalidMessages (void(*invalFunction)(SharedInvalidationMessage *msg), void(*resetFunction)(void))
 
void HandleCatchupInterrupt (void)
 
void ProcessCatchupInterrupt (void)
 

Variables

uint64 SharedInvalidMessageCounter
 
volatile sig_atomic_t catchupInterruptPending = false
 

Macro Definition Documentation

◆ MAXINVALMSGS

#define MAXINVALMSGS   32

Function Documentation

◆ HandleCatchupInterrupt()

void HandleCatchupInterrupt ( void  )

Definition at line 154 of file sinval.c.

155 {
156  /*
157  * Note: this is called by a SIGNAL HANDLER. You must be very wary what
158  * you do here.
159  */
160 
162 
163  /* make sure the event is processed in due course */
164  SetLatch(MyLatch);
165 }
struct Latch * MyLatch
Definition: globals.c:60
void SetLatch(Latch *latch)
Definition: latch.c:632
volatile sig_atomic_t catchupInterruptPending
Definition: sinval.c:39

References catchupInterruptPending, MyLatch, and SetLatch().

Referenced by procsignal_sigusr1_handler().

◆ ProcessCatchupInterrupt()

void ProcessCatchupInterrupt ( void  )

Definition at line 174 of file sinval.c.

175 {
177  {
178  /*
179  * What we need to do here is cause ReceiveSharedInvalidMessages() to
180  * run, which will do the necessary work and also reset the
181  * catchupInterruptPending flag. If we are inside a transaction we
182  * can just call AcceptInvalidationMessages() to do this. If we
183  * aren't, we start and immediately end a transaction; the call to
184  * AcceptInvalidationMessages() happens down inside transaction start.
185  *
186  * It is awfully tempting to just call AcceptInvalidationMessages()
187  * without the rest of the xact start/stop overhead, and I think that
188  * would actually work in the normal case; but I am not sure that
189  * things would clean up nicely if we got an error partway through.
190  */
192  {
193  elog(DEBUG4, "ProcessCatchupEvent inside transaction");
195  }
196  else
197  {
198  elog(DEBUG4, "ProcessCatchupEvent outside transaction");
201  }
202  }
203 }
#define elog(elevel,...)
Definition: elog.h:224
#define DEBUG4
Definition: elog.h:27
void AcceptInvalidationMessages(void)
Definition: inval.c:806
bool IsTransactionOrTransactionBlock(void)
Definition: xact.c:4910
void StartTransactionCommand(void)
Definition: xact.c:2955
void CommitTransactionCommand(void)
Definition: xact.c:3053

References AcceptInvalidationMessages(), catchupInterruptPending, CommitTransactionCommand(), DEBUG4, elog, IsTransactionOrTransactionBlock(), and StartTransactionCommand().

Referenced by HandleAutoVacLauncherInterrupts(), and ProcessClientReadInterrupt().

◆ ReceiveSharedInvalidMessages()

void ReceiveSharedInvalidMessages ( void(*)(SharedInvalidationMessage *msg)  invalFunction,
void(*)(void)  resetFunction 
)

Definition at line 69 of file sinval.c.

71 {
72 #define MAXINVALMSGS 32
73  static SharedInvalidationMessage messages[MAXINVALMSGS];
74 
75  /*
76  * We use volatile here to prevent bugs if a compiler doesn't realize that
77  * recursion is a possibility ...
78  */
79  static volatile int nextmsg = 0;
80  static volatile int nummsgs = 0;
81 
82  /* Deal with any messages still pending from an outer recursion */
83  while (nextmsg < nummsgs)
84  {
85  SharedInvalidationMessage msg = messages[nextmsg++];
86 
88  invalFunction(&msg);
89  }
90 
91  do
92  {
93  int getResult;
94 
95  nextmsg = nummsgs = 0;
96 
97  /* Try to get some more messages */
98  getResult = SIGetDataEntries(messages, MAXINVALMSGS);
99 
100  if (getResult < 0)
101  {
102  /* got a reset message */
103  elog(DEBUG4, "cache state reset");
105  resetFunction();
106  break; /* nothing more to do */
107  }
108 
109  /* Process them, being wary that a recursive call might eat some */
110  nextmsg = 0;
111  nummsgs = getResult;
112 
113  while (nextmsg < nummsgs)
114  {
115  SharedInvalidationMessage msg = messages[nextmsg++];
116 
118  invalFunction(&msg);
119  }
120 
121  /*
122  * We only need to loop if the last SIGetDataEntries call (which might
123  * have been within a recursive call) returned a full buffer.
124  */
125  } while (nummsgs == MAXINVALMSGS);
126 
127  /*
128  * We are now caught up. If we received a catchup signal, reset that
129  * flag, and call SICleanupQueue(). This is not so much because we need
130  * to flush dead messages right now, as that we want to pass on the
131  * catchup signal to the next slowest backend. "Daisy chaining" the
132  * catchup signal this way avoids creating spikes in system load for what
133  * should be just a background maintenance activity.
134  */
136  {
137  catchupInterruptPending = false;
138  elog(DEBUG4, "sinval catchup complete, cleaning queue");
139  SICleanupQueue(false, 0);
140  }
141 }
uint64 SharedInvalidMessageCounter
Definition: sinval.c:24
#define MAXINVALMSGS
void SICleanupQueue(bool callerHasWriteLock, int minFree)
Definition: sinvaladt.c:577
int SIGetDataEntries(SharedInvalidationMessage *data, int datasize)
Definition: sinvaladt.c:473

References catchupInterruptPending, DEBUG4, elog, MAXINVALMSGS, SharedInvalidMessageCounter, SICleanupQueue(), and SIGetDataEntries().

Referenced by AcceptInvalidationMessages().

◆ SendSharedInvalidMessages()

void SendSharedInvalidMessages ( const SharedInvalidationMessage msgs,
int  n 
)

Definition at line 47 of file sinval.c.

48 {
49  SIInsertDataEntries(msgs, n);
50 }
void SIInsertDataEntries(const SharedInvalidationMessage *data, int n)
Definition: sinvaladt.c:370

References SIInsertDataEntries().

Referenced by AtEOXact_Inval(), CacheInvalidateRelmap(), CacheInvalidateSmgr(), FinishPreparedTransaction(), and ProcessCommittedInvalidationMessages().

Variable Documentation

◆ catchupInterruptPending

volatile sig_atomic_t catchupInterruptPending = false

◆ SharedInvalidMessageCounter

uint64 SharedInvalidMessageCounter